This invention relates to a connector capable of transmitting high-speed differential signals.
A connector of the type is used as an interface connector or an internal connector of a digital appliance or a PC. Such connector includes a plurality of signal contacts and a plurality of ground contacts. The signal contacts are paired in order to transmit differential signals in the manner known in the art. Generally, on the side of a fitting portion or a contacting portion side of the connector to be fitted to or contacted with a mating connector, the signal contacts and the ground contacts are arranged in a single row. On the other hand, on the terminal portion side of the contacts to be connected to a board, the terminal portions are arranged in a plurality of rows because the terminal portions are inserted into a plurality of through holes, respectively. Thus, so-called pitch conversion is performed between the contacting portions and the terminal portions of the contacts.
For example, in a connector disclosed in Japanese Unexamined Patent Application Publication No. 2002-334748 (JP 2002-334748 A), the contacting portions are arranged so that a plurality of sets of one ground contact (G) and two signal contacts (S) as paired signal contacts are alternately consecutively arranged (G, S, S, G, S, S, . . . ). In this event, in case of normal pitch conversion, an imbalance is caused in physical distance between the ground contact and the paired signal contacts on the side of the terminal portions.
As a result, the connector may be deteriorated in transmission characteristics so that a performance for high-speed transmission can not be satisfied.